Graduated tension device for sewing machines



June 14, 1932.

D. H. CHASON 1,862,658

GRADUATED TENSION DEVICE FOR SEWING MACHINES Filed June 1, 1931 Illlll Patented June 14, 1982 UNITED STATES PATENT GFFEGE DANIEL H. GHASON, 07? ELIZABETH, NEW JERSEY, ASSIGNOB TO THE SINGER MANU- FAGTURING COMPANY, ELIZABETH, NEW JERSEY, A CORPORATIGN OF NEW JERSEY GBADUATED TENSION DEVICE FOR SEWING MACHINES Application filed June 1, 1931.

This invention relates to thread-tension devices for sewing machines, and more particularly to thread-tension devices of the type having a graduated scale and an indicator cooperating therewith to show the degree of tension applied to the thread.

The invention has for an object to provide a graduated tension-device having the usual torsion check-spring associated therewith in which there is provision for adjusting the tension of the check-spring and retaining the graduated scale in its desired readily visible position. A further object of the invention is to provide a sewing machine tension and check-spring assembly which is simple in construction and in expensive to manufacture and the parts of which may be readily as sembled and adjusted.

Further objects of the invention will appear as the description proceeds.

The invention comprises the devices, combinations and arrangements of parts hereinafter described and claimed.

The features of the invention and the advantages attained thereby will be readily understood by those skilled in the art from the following detailed description of a preferred embodiment of the invention illustrated in the accompanying drawing of which Fig. 1 is a face view of the needle-bar head of a sewing machine head carrying a tension device embodying the invention. Fig. 2 is a top plan view of the tension device. 3 is a. section on the line 3-3. Fig. 2. Fig. 4 is a section on the line H, of Fig. 2. Fig. 5 is a section on the line 5 5. Fig. 2. Fig. 6 is a disassembled perspective view of the tension device. Fig. 1 is a perspective view of the support for the arbor of the tension de vice. Fig. 8 is a perspective view of a sleeve received within the support shown in Fig. 7, and Fig. 9 is a rear face view of the support shown in Fig. 7.

1 represents the usual faceplate secured to the head at the free end of the bracket-arm Serial No. 541,285.

of a sewing machine; such head carrying the usual reciprocating needle-bar 2 and presserbar 3 supporting the needle 4 and presser-foot 5, respectively. Riveted to the face-plate 1, is the central supporting stud 6 in which is tired by means of the set-screw 7 one end of the tension-supporting arbor 8. Surrounding the supporting stud 6 and spaced from the latter is the stationary sleeve 9 having projections 10 at one end which are riveted in apertures in the face-plate 1. A circularly adjustable sleeve 11 is received with the fixed sleeve 9 and is formed with a clearance slot 19. for the set-screw 7. The adjustable sleeve 11 has threaded into its side wall a clamping screw 13 which passes through a clearance slot 14; in the side wall of the fixed sleeve 9.

There is coiled about the arbor 8 the usual torsion check-spring 15 one end 16 of which is anchored in a slot 17 in such arbor. The other end of the torsion check-spring 15 is extended outwardly at 18 and at its free end is bent into the form of a thread-engaging loop or hook 19. The portion 18 of the checkspring is limited in its movement in one direction by the stop-ledge 20 formed at one end of the adjustable sleeve 11. Circular adjustment of the sleeve 11 determines the stopped position of the looped end 19 of the cheek-spring. lhe tension of the checkspring may be adjusted by loosening the setscrew 7 and turning the arbor 8 in its socket in the supporting stud 6, subsequently tightening the screw 7.

Seated against one end of the rotatable sleeve 11 is the usual abutment disk 21 from which is struck rearwardly the tongue 22 entering the anchor slot 23 in the stationary sleeve 9. The abutment disk 21 has a central clearance aperture for the arbor 8. Loose on the arbor 8. adjacent the abutment disk 21. are the usual; tension disks 24 between which the sewing thread passes. Bearing upon the outer tension disk 24 is the headed end 25 of a tubular member 26 formed in its upper side wall with a slot 27 along one edge of which is marked a graduated scale. The headed end 25 of the tubular member 26 is formed with a central depression 28 in which is received an anchordisk 29 having a diameter-bar 30 passing through the slot 31 in the arbor S. The anchor-disk 29 is formed with a tongue 32 which enters a selected one of the circular series of apertures 33 formed in the depressed portion of the head 25 of the sleeve 26.

Telescoped within the tubular member 26 is a tubular member 34 carrying an outwardly projecting indicator 35 which passes through the slot 27 and plays over the grad uated scale at the edge of the slot 27. There is housed within the telescopically arranged members 26 and 34 a beehive tension-spring 36 the base end of which is entered by the depression 28 in the head 25 of the tubular member 26. A tension regulating nut 37 is screwed onto the arbor 8 and bears against the headed end 38 of the tubular member 34.

Disposed in an axial aperture in the arbor 8 is the endwise movable tensionrelease pin 39 one end of which is adapted to engage the diameter-bar 30 of the anchor disk 29 and push the latter and the tubular member 26 in a direction to relieve the tension-disks 24 of the pressure of the tension-spring 36. The tension-release pin 39 is actuated as usual by the cam 40 on the presser-foot lifting lever 41 which is fulcrumed at 42 on the sewing machine frame.

It will be evident from the foregoing that adjustment of the tension of the check-spring 1.5 is eifected by rotatively adjusting the arher 8 about its axis. This adjustment of the arbor 8 will more or less displace the slot 27 and its graduated scale from the desired visible position on the upper side of the tension device. The provision of an additional anchor disk 29 to which the sleeve 26 is adjustably connected by means of the tongue 32 and series of apertures 33, permits the tubular member 26 to be adjusted or reset to the desired position from which it was displaced. There is thus provided a simplified graduated tension and check-spring assembly in which adjustment of the tension on the checkspring may be made without permanently displacing the graduations and indicator for the main tension-spring from their desired visible position.

Having thus set forth the nature of the invention, what I claim herein is 1. A sewing machine tension-device having a support. an arbor rotatabl adjustable about its axis in said support, a torsion checkspring anchored at one end to said arbor, a main tension-spring, a first member anchored against rotation relative to said arbor, a second member adj ust-ably anchored to said first-mentioned member and bearing a tension indicating scale, and a tension-regulating device including a tension-regulating nut and an indicator playing over said scale.

2. A graduated tension-device for sewing machines having, a longitudinally slotted supporting arbor, a pair of telescopically arranged tubular members surrounding said arbor, one of which members is provided with a scale and the other with an indicator playing over said scale, one of said members having a head at one end, a third member anchored against rotation relative to said arbor and to which said head is adjustably anchored, a thread-tension spring housed within said tubular members, and an arbor support relative to which said arbor is rotatably adjustable.

3. A graduated tension-device for sewing machines having, a longitudinally slotted supporting arbor, a pair of telescopically arranged tubular members surrounding said arbor, one of which members is provided with a scale and the other with an indicator playing over said scale, one of said members having a head at one end, a third member anchored against rotation relative to said arbor, said third member and the headed end of one of the tubular members having interengaging projection and depression means permitting circular adjustment of the telescopic members relative to said supporting arbor.

4. A tension device for sewing machines having a support, a slotted arbor carried by said support and adjustable circularly about its axis, a check-spring anchored at one end to said arbor, a pair of tension disks loose on said arbor, a pair of telescopically arranged tubular members on said arbor, a beehive tension-spring housed within said tubular members, one of said tubular members having a graduated scale on its side wall and a head in one end formed with a central de pression entering the base end of said beehive spring, a tension regulating nut engaging the other tubular member, and an anchor disk received in said depression and formed with a diameter-bar received in the slot in sald arbor. said anchor disk belng ad ustably connected to the adjacent wall of said depresdisks loose on said arbor, a tubular member having a headed end adapted to engage one of said tension-disks and formed with a depression to receive said anchor-disk, means for adjustably anchoring the headed end of said tubular member to said anchor-disk, a second tubular member telescopically received in the first mentioned tubular member, a tension-spring housed by said tubular members, and a tension-regulating nut engaging the second-mentioned tubular member, one of said tubular members having a scale and the other an indicator playing over said scale.

In testimony whereof I have signed my name to this specification.

DANIEL H. CHASON. 

